New refining process could lower cost of titanium by 60%

Researchers at Case Western Reserve University (CWRU) have been selected by ARPA-E, the US government's Advanced Research Projects Agency - Energy, to carry out a one year project aimed at developing a low cost method to obtain titanium metal from its ore. It is thought that the process could lower the cost of the metal by up to 60 percent.

Titanium can be made into structural materials that are extremely strong for their weight and show excellent resistance to corrosion. It is used in a number of high-value applications in aerospace, defense, medicine, and transportation. Although titanium and its alloys could be used in many other applications, titanium metal is notoriously difficult to refine and purify from its various ores.

The cost of titanium metal is currently about six US dollars per kilogram, compared to steel at under a dollar per kilogram, and aluminum alloy at under two dollars per kilogram. About half of this is the cost of magnesium metal that is used up in the refining process. Fabricating titanium products is also rather difficult, with the result that titanium is used in very few products in which another structural metal is found satisfactory.

The $675K ARPA-E award will be used by the CWRU team, led by Associate Professor Rohan Akolkar, will be developing a process based on electrowinning, a form of electroplating, to directly extract titanium from molten titanium salts. Electrolytically extracted titanium is expected to contain fewer impurities and therefore have superior mechanical properties as extracted.

The team’s proposal has the potential of considerably expanding the domestic titanium production industry and lower reliance on titanium imports. While cheaper titanium will not solve the difficulties in fabricating titanium products, it should make this very useful metal practical to use in a wider range of products that can benefit from its desirable mechanical and chemical properties.